We can add to our ToDo list to document which ones exist, but the idea is that you should use the image selector that best matches the state you want regardless of if the icon exists currently. That is so that some day when a more precise state icon is added to Indigo it will then be shown without any plugin change needed.

...some day in the future when a more precise state icon is added to Indigo it will then be shown without any plugin change needed.

Got it. Though, in some cases a developer might pick one icon to use for now until a more appropriate image becomes available. Also, for example, I might not get involved with the case logic to determine wind direction if I knew the icon wasn't available.

I might not get involved with the case logic to determine wind direction if I knew the icon wasn't available.

Seems like if the wind direction is useful to users, it would be a shame to not provide it just because there's no icon...

It was just an example. But, since you bring it up... the wind gauge already reports in degrees. But, wind speed is more important than direction, so I map speed to the device display state. If I could overlay direction, as an icon, that would be a plus.